Projectiles, such as guided missiles, mortar rounds, and the like, are often stored, shipped, and carried to their point of deployment in canisters. Among other things, a canister protects a projectile from harsh environmental conditions. A typical canister comprises a launch tube that guides the projectile as it is launched, much like the launch tube of a gun. At deployment, the projectile is propelled from its canister using either its self-propulsion engine or by external means such as an electromagnetic launcher, compressed gas, mechanical catapult, and the like.
Typically, each projectile is secured within its canister by a mechanical release restraint in order to avoid damage during transport. In order to launch the projectile, the restraint is actuated to release it from its canister. This enables the projectile to be propelled from the canister. Restraints known in the prior-art include explosive bolts, marmon clamps, bullet jackets, and shape charges.
These restraints have several drawbacks, however. First, they require proactive actuation in the form of electromechanical, motor driven, or explosives. As a result, additional infrastructure and/or control signals are required to make them release their projectile. This increases the complexity and cost of the launch systems in which they are employed.
Second, many canisters are designed with reload capability so that they can be reused to launch additional projectiles. Since many of these restraints leave residue or other material behind after their actuation during the launch of their projectile. This residual material must be removed prior to a subsequent launch. For systems capable of multiple launches, therefore, the time between consecutive launches is increased. This decreases the overall firepower of the launch system. In addition, additional labor and/or personnel are required to remove the residual material.
Finally, the need to proactively actuate these prior-art restraints leads to a reliability issue. If an actuation signal is not sent to the restraint, or the actuation signal is not received by the restraint, a catastrophic accident, such as the detonation of a projectile within its canister, can ensue.
Therefore, the need exists for a restraint that avoids or mitigates some or all of these problems.